Experiments will be carried out to study regulation of catecholamine synthesis and release in the rat central nervous sytem. Preparations representing different levels of cellular organization will be utilized, including (1) free enzymes, (2) isolated synaptosomes (nerve-endings) and (3) in vivo systems. The regulatory properties of the norepinephrine-rich catecholamine-forming synaptosomes in the hypothalamus, hippocampus and cerebellum will be analyzed and compared to the striatum, a dopamine-rich area which we have been extensively studying. This comparison will allow us to determine if the basic regulatory properties of these two catecholamine systems are similar and also to compare the effects of psychoactive drugs on noradrenergic versus dopaminergic neurons. (The psychoactive drugs to be studied will include neuroleptics, tricyclic antidepressants, lithium and stimulant drugs of abuse.) These studies will be of importance to the field of psychiatry, since the catecholamines (both dopamine and nonrepinephrine) have been implicated in playing major roles in psychiatric disorders such as schizophrenia and the affective disorders such as depression and mania.